Method for improving the color number of trimethylolpropane

Abstract

The present invention relates to a method for the production of trimethylolpropane with a low color number by treatment with activated carbon.

1. A method of producing trimethylolpropane having a low color number, comprising: contacting essentially pure, liquid TMP with activated carbon and separating off the activated carbon, wherein the activated carbon has a BET surface area from 500 to 2500 m 2 /g. 
     
     
       2. The method as claimed in  claim 1 , wherein the essentially pure trimethylolpropane has a trimethylolpropane content of from 90 to 100% by weight. 
     
     
       3. The method as claimed in  claim 1 , wherein the process is carried out at from 80 to 200° C. 
     
     
       4. The method as claimed in  claim 1 , wherein the activated carbons are those selected from the group consisting of wood charcoal, brown coal, hard coal, peat, wood, coconut shells and olive stones. 
     
     
       5. The method according to  claim 1 , wherein the contacting of the essentially pure trimethylolpropane with activated carbon takes from 1 min to 24 h. 
     
     
       6. A method of producing trimethylolpropane having a low color number, comprising: contacting essentially pure, liquid TMP with a plurality of activated carbon beds wherein, at least one carbon bed is regenerated after contact with the essentially pure, liquid TMP.